Module 1
What was the first virus of vertebrates that was discovered?
Foot-and-mouth disease
Describe the general structure of a virus.
Nucleic acid (DNA or RNA) surrounded by a capsid and possibly an envelope.
What are localized infections?
Limited to the sites of entry of the virus.
What are some reasons that a clinician may wish to confirm a diagnosis of a specific virus?
If there's economic importance of the disease.
If they're unable to establish an unequivocal diagnosis.
Diagnosis allows for effective control of disease.
The most successful vaccines are what type of vaccine?
Attenuated.
Finish the quote. "The future for you is the century of ________"
Genetics
An infected animal devlops antibodies to what part of the virus?
The proteins of the capsid or the envelope. This is the basis for vaccine development.
What is virulence?
A relative measure of the pathogenicity of the infecting virus.
What virus isolation technique is used for influenza viruses and was historically used for pox virus isolation?
Embryonated eggs.
All vaccines should satisfy what requirements?
Efficacy, purity, potency, and safety.
What are Koch's postulates?
Agent present in every case.
Agent isolated from the host and grown in vitro.
Disease reproduced in a healthy host.
The same agent is once again isolated from the new host.
______ generally means that immunity in not conferred by previous exposure to a different type.
"Serotype"
What is tropism?
Some viruses have specific affinity for particular systems (e.g rabies virus is neurotropic)
ELISA for FeLV and FIV are looking for what?
Antigen for FeLV and antibody for FIV.
How do marker vaccines work?
Certain antigenic genes have been removed, so animals vaccinated won't have antibodies for these genes while animals naturally infected will have antibodies for those genes.
Recombinant DNA
What allows a virus to infect a cell?
Both viruses and cells need to have receptors and an affinity between them that results in attachment.
Why do we booster vaccines in babies?
Because maternal antibodies will block the effectiveness of vaccines given.
What is the predominant laboratory test in identification of a virus?
PCR
What are the advantages of inactivated vaccines?
They are stable and have no possibility of spreading disease.
What was the second paradigm shift in the 1980s?
Computer technology.
What are some cytopathic effects in cell culture?
Inclusions - intranuclear bodies.
Plaques
Cells lose the property of cell inhibition and pile up.
Describe innate resistance, induced resistance, and acquired immunity.
Innate resistance are genetic or non-specific like mucus barrier.
Induced resistance is the innate immune system (phagocytosis, complement, inflammation).
Acquired resistance in the adaptive immune system (antibodies and cell-mediated).
What is the important thing to remember about the interpretation of laboratory findings?
The laboratory doesn't provide you with THE diagnosis, it provides you with information upon which to base your diagnosis.
Name four reasons vaccines may fail to protect.
Improper use.
Genetic differences between animals.
Antigenic differences.
Blocking by maternal antibodies.
Administration following infection.